The present invention concerns a method for the insertion and starting of thread in a false-twist texturing device, which device possesses a fluid containing heat exchanger with at least two passages for the leading through of thread and for the sealing of the heat exchanger. Moreover, the present invention relates to a false-twist texturing device with a heat exchanger having at least two thread passages for the conducting of the thread therethrough and for the sealing of the heat exchanger.
EP 0 624 208 B1 discloses a texturing device, in which heat exchangers are provided. The heat exchangers are installed for optional service as a heating apparatus or as a cooling apparatus. In each case fluid, hot or cold, is brought into contact with the thread. The fluid, in this operation, finds itself in a chamber through which fluid is continually flowing. The chamber is essentially constructed in tubular form and possesses small borings, through which the thread is brought into and out of the vessel. An exchange of heat is effected by means of the contact of the thread with the fluid. If the fluid is warmer than the thread, then the thread is warmed. If the fluid is cooler than the thread, the thread is cooled. Although this known apparatus operates satisfactorily, a disadvantage lies therein, in that in the case of a thread break, or if a restart of the texturing of the thread in the tubular vessel becomes necessary, then the thread must be reintroduced into the tubular vessel. This is very expensive in time and money, since, in order to restart the process, the thread must be inserted through very small openings in the tubular chamber. These starting operations in the case of this known apparatus is thus complicated and time consuming.
Thus, a principle object of the present invention is to create a process and an apparatus, wherein the insertion and the starting, that is, the restart of the texturing process, can be carried out quickly, simply and reliably. Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
This above described object is achieved by a method in accord with the generic method, in which the thread passages are increased in size for the introduction of the thread. By means of the increased size of the thread passages, it becomes possible in a simple manner to insert the thread into the heat exchanger. The danger of a blockage of the thread passages is assuredly avoided with this arrangement. If, in an advantageous formulation of the invention, the thread passages are separable in an axial and/or radial direction for the introduction of the thread, and are thereupon closed following the introduction of thread, an especially simple and problem-free entry of the thread becomes possible. Where this procedure is concerned, the narrowly confined thread passages are opened, and thus, in a very simple manner, it becomes possible to lay the theread in an opened groove instead inserting it into a restricted, small opening. The thread, so inserted, by the subsequent closure of the thread passages, is once again totally enclosed in the passages, since the once exposed groove becomes a fully circumferentially enclosed passage upon being closed. The insertion of the thread by this method is very rapid, simple and reliable to carry out.
An object of the invention is further achieved, in that the thread, by means of an auxiliary air flow through the thread passages, is either blown or sucked through the thread passages.
By means of a corresponding arrangement of air nozzles, which empower the auxiliary air flow through the thread passages, the thread is entrained in the air flow and carried through the thread openings. In this case, obviously, an opening of the thread passages is not required and the entry and subsequent thread-start is thus activated by an especially simple, constructive apparatus. The auxiliary nozzles can be placed at each thread passage and thus act in the manner of a progressive nozzle arrangement, whereby the thread is carried along from nozzle to nozzle.
Further, the purpose of the invention will be achieved, in that the thread is pulled through the thread passages by means of an awl. In many cases of insertion in which the auxiliary air flow might not be sufficient, by means of an awl, which has been previously pushed through the thread passage, the thread can be captured thereon and then pulled through the thread passage. In many applications, this can be an advantage, since a mechanical guidance is available for the thread and the insertion is clearly made easier thereby.
In order to prevent the fluid of the heat exchanger escaping from the heat exchanger through the thread passages, in accord with the invention, a second fluid flow, in particular an air flow, restrains the first fluid from access to the thread passages. This second fluid flow, specifically an air flow, enters the heat exchanger in the area of the thread passages and accordingly generates a flow, that is, a pressure, which acts contrary to the escape tendency of the first fluid. In this way, an active sealing off of the thread passages is accomplished, so that the heat exchanger can even be so constructed, that the thread passages are placed in a vertical direction.
In order to prevent the first fluid from running out of the heat exchanger upon the insertion of the thread, provisions are made that, before the insertion of the thread (i.e., before the opening of the heat exchanger), the feed of the first fluid and/or the second fluid is interrupted and the fluid in the heat exchanger is removed. By this means, a simple insertion, or a guiding of the thread into the heat exchanger now empty of fluid, is possible. Thus, simple methods of insertion of thread now encompass both the use of an auxiliary flow of air as well as the opening of the heat exchanger.
To allow the thread to pass through the heat exchanger in a manner as free as possible from stress and thereby to avoid a thread break, provisions are made so that the thread travels only at a restrained speed after the inlay or insertion of the thread and then is increased to the operational level. In this way, the force, which the fluid exerts on the thread, is gradually increased so that a thread break is avoided.
The object will also be achieved by a false twist texturing device with a heat exchanger with at least two thread passages for the passage of the thread and for the sealing of the heat exchanger. In this case, the heat exchanger is separated along the direction of the thread movement, and the parts which allow the simple inlay of the thread can be parted one from the other. With an apparatus of this description, it is possible to open the heat exchanger so far that the thread can be inserted into the heat exchanger. The thread passages are made simple to access by the opening of the heat exchanger, so that the thread, in accord with the formation of the thread passage can be guided into the thread passages or laid across them with simple means. Following this inlay or insertion of the thread into the thread passages, the heat exchanger can be again closed, whereupon it is ready for operation. The complicated threading of the thread through the complete heat exchanger from the thread inlet to the thread outlet, as is necessary in the state of the technology today, is advantageously no longer required because of the invented method.
In the case of a separable heat exchanger, as well as where a single piece heat exchanger is concerned, provisions can be made for an injector nozzle to be placed before and/or after the individual thread passages at the respective inlet and/or outlet to transport the thread through the thread passage. The injector nozzle produces such an effect, that according to the passage design, the thread is guided through the thread passages by means of either a blowing or a suction action. The injector nozzle, for this action, can be integrated into the heat exchanger or principally brought to the heat exchanger when a thread input procedure is called for. If seen as advantageous, an individual nozzle can be installed in front of each thread passage and another following the thread passage to achieve a reliable insertion of the thread. Often it suffices to simple place an injector nozzle at the first and/or the last thread passage of the heat exchanger, whereby the thread can be blown or sucked through the heat exchanger.
If, within the heat exchanger, the thread inlet and the thread outlet are connected by a tube with passages radially situated along its length, then the air flow with which the thread is brought through the thread passages also flows through the heat exchanger. In this way, the thread is mechanically led through the heat exchanger. By means of the passages in the tube, assurance is provided that the fluid in the heat exchanger comes into sufficient contact with the thread.
If the thread passages are made in segments that are individually movable in reference to one another, so that the thread passages can open in an axial or a radial manner for the insertion of the thread, then an especially simple inlay of the thread is accomplished. Because the thread grooves of the segments are circumferentially constituted so that the thread in one of the segments per thread passage is laid in one groove, and subsequently the thread passage is closed to match a corresponding groove of another segment, then, in operation, an excellent placement of the thread has been accomplished as well as an effective sealing action of the thread passages relative to the active fluid of the heat exchanger. In other words, the segments are, in accomplishing this operation, separated from one another for the inlay of the thread, and, after the inlay of the thread, are brought into alignment again, so that the circumferential capture of the thread in the passage is carried out by this means. Frequently, it suffices if the two coacting segments are arrayed in an axial direction, one behind the other, and abutting one another on one side to maintain a satisfactory sealing action.
In a particularly advantageous embodiment, the segments relate to one another in a rotatably arranged, circular part of the thread passage. With this arrangement, in a particularly simple manner, the opening of the thread passage for the inlay of the thread and the subsequent closure of the thread passage makes possible a circumferential capture of the thread.
In order to bring about an advantageous sealing action in the axial direction of the individual segments, at least one of the coacting, individual segments is loaded by a spring against the corresponding segment. The side surfaces of the segments engage against one another in a substantially sealing manner, so that the fluid present in the heat exchanger is essentially prevented from penetrating backward through the thread passage. By means of this spring loaded placement of at least one of the segments, the opening and the closing of the thread passages is made easier, and the tolerances which must be maintained in the process of manufacture are less demanding. Thereby, a simple and enduring, tight closure ability of the thread passage can be effected.
In order to prevent a loss of the fluid present in the heat exchanger, provisions have been made so that at least the chamber of the heat exchanger in which the first fluid is to be found is sealed by means of a peripheral sealant. When this is done, the opening and closing of the heat exchanger is advantageously possible for a longer period without the loss of the heat transfer fluid, which fluid, for example, would have to be retained in separate tanks.
In order to achieve an especially effective temperature exchange between the fluid and thread, provisions have been made that the flow of fluid through the heat exchanger proceeds in counterflow to the progress of the thread therethrough. Experience has shown, that in such opposite movement, the thread approaches the temperature of the fluid essentially more rapidly. The length of the heat exchanger on this basis can be reduced under certain temperature differences and exchange dwell time. Alternatively, the transport velocity of the thread through the heat exchanger may accordingly be increased. In general, it has been established, that it is advantageous for the fluid flow through the heat exchanger to be provided with velocity components which are relative to differing thread velocity components.
If the fluid flow is in a direction essentially contrary to the pull of gravity, then a particularly simple possibility for the through-flow is produced.
In order to attain a particularly effective sealing action in the area of the thread passages and to prevent the issuance of the fluid from the heat exchanger at, these passage points, the invention provides that more than one, preferably three, thread passages are positioned at the thread inlet and/or thread outlet. By this means, a kind of a labyrinthine sealing means can be installed which reliably assures that the heat exchanger is tight. In this way, it is even possible to place the heat exchanger in a vertical position, so that the thread inlet or outlet can be located under the fluid container of the heat exchanger.
In order to simplify the insertion of the thread, especially in the case of injector nozzles, provisions have advantageously been made, so that the thread passage is equipped with a chamfered entry to accept the thread insertion. In this way, the flow and the thread are so guided, that the thread penetrates the openings of the thread passages without difficulties and a thread blockage within the heat exchanger is avoided.
Since the thread runs through the thread passage at very high speeds, it is particularly advantageous, if the thread passage is designed to be wear resistant. In this regard, ceramics have proven themselves especially advantageous, in that first, they, show a high wear resistance in regard to the thread, and second, the thread passes through essentially in an undamaged condition.
In order to prevent the heat exchanger from accidentally opening, especially when there is still fluid in the heat exchanger, it is advantageously provided that the heat exchanger can be locked, especially mechanically, electrically, hydraulically or pneumatically. Only upon a signal that opening is permissible after an emptying of the heat exchanger, would it be possible for the heat exchanger to be opened manually or automatically.
It is particularly advantageous if the fluid is water and specifically, distilled water, so that an especially more rapid and simpler heat transfer can take place. Water contact is not a negative influence on the thread and permits either a protective cooling or heating of the thread to a currently desired temperature. Beyond this, the water is economical to use and creates no problems if the heat exchanger, in case of damage, loses its sealing and the fluid escapes.
If the fluid possesses thread treatment additives and/or a specified degree of hardness, then the thread, on an optional basis, can be treated during the texturing procedure or be especially prepared for further processing.
Great advantages have arisen, when a fluid, particularly water, is used which has been enriched or saturated with a scrooping agent. By this means, the thread receives great protection in subsequent treatment, and a washing-out of the thread is prevented. In this way, a very high quality thread is produced.
If the fluid possesses a specified temperature, then the temperature change of the thread likewise can be predetermined from the dwell time of the thread in the heat exchanger. By means of a change in the temperature of the fluid, then correspondingly, changes in the temperature of the thread can be effected. In this way, a balancing can be made when the thread enters into the heat exchanger at different temperatures or the temperature of the thread is too high or too low at the thread exit. By a temperature change of the fluid, in these cases, the thread can be held at a uniform temperature.
For the support of the labyrinthine sealing means at the thread inlet and outlet passages, the invention provides another fluid, preferably air, to be admitted in the area of the passages for the sealing of the heat exchanger and/or for the drying of the thread. The air acts in this manner, especially when at a certain pressure, perhaps lower than 5 bar, preferably 0.5 bar, against the first fluid in the heat exchanger and prevents the first fluid from migrating through the thread passages. In this way, a particularly tight sealing of the heat exchanger is attained. As a further effect, the drying of the thread is carried out by this second fluid, especially when it is air or another gaseous medium. By the above mentioned means, a leakage of the first fluid of the heat exchanger to the outside of the heat exchanger, and the consequent contamination of the surroundings is reliably avoided. In particular, the effect of the drying of the thread has proven itself as being extraordinarily positive, since even the further workup of the thread can be carried out without difficulties. The disadvantage of the previously employed, fluid-using heat exchangers is reliable avoided, by the above means, and in accord with the invention.
In a further embodiment in accord with the present invention, the heat exchanger is variable in its length, in this case being telescopically constructed. By this means, the dwell time of the thread in the heat exchanger can be correspondingly variably set. This concept of the heat exchanger, realized here for the first time with a variable length, leads to particularly favorable operational characteristics, since the heat exchanger can now be very simply adapted to the current application. If the contact positions of two telescopic parts of the heat exchanger are likewise supplied with a sealing means, then also in this situation, an effective sealing is achieved for the chamber in which the first fluid is contained. Obviously, there are other sealing possibilities which can be put into use, for instance, a casing of variable length inside the heat exchanger where the first fluid is held.